| /* |
| * This file is part of the Jikes RVM project (http://jikesrvm.org). |
| * |
| * This file is licensed to You under the Eclipse Public License (EPL); |
| * You may not use this file except in compliance with the License. You |
| * may obtain a copy of the License at |
| * |
| * http://www.opensource.org/licenses/eclipse-1.0.php |
| * |
| * See the COPYRIGHT.txt file distributed with this work for information |
| * regarding copyright ownership. |
| */ |
| package org.mmtk.plan.markcompact; |
| |
| import org.mmtk.plan.*; |
| |
| import org.mmtk.vm.VM; |
| |
| import org.vmmagic.pragma.*; |
| import org.vmmagic.unboxed.*; |
| |
| /** |
| * This class implements <i>per-collector thread</i> behavior |
| * and state for the <i>MC</i> plan, which implements a full-heap |
| * mark-compact collector.<p> |
| * |
| * Specifically, this class defines <i>MC</i> collection behavior |
| * (through <code>trace</code> and the <code>collectionPhase</code> |
| * method), and collection-time allocation.<p> |
| * |
| * @see MC for an overview of the mark-compact algorithm.<p> |
| * |
| * FIXME Currently MC does not properly separate mutator and collector |
| * behaviors, so some of the collection logic in MCMutator should |
| * really be per-collector thread, not per-mutator thread. |
| * |
| * @see MC |
| * @see MCMutator |
| * @see StopTheWorldCollector |
| * @see CollectorContext |
| */ |
| @Uninterruptible public class MCCollector extends StopTheWorldCollector { |
| |
| private static final boolean TRACE_MARK = false; |
| private static final boolean TRACE_FORWARD = true; |
| |
| /**************************************************************************** |
| * Instance fields |
| */ |
| |
| private final MCMarkTraceLocal markTrace; |
| private final MCForwardTraceLocal forwardTrace; |
| private boolean currentTrace; |
| |
| /**************************************************************************** |
| * |
| * Initialization |
| */ |
| |
| /** |
| * Constructor |
| */ |
| public MCCollector() { |
| markTrace = new MCMarkTraceLocal(global().markTrace); |
| forwardTrace = new MCForwardTraceLocal(global().forwardTrace); |
| } |
| |
| |
| /**************************************************************************** |
| * |
| * Collection-time allocation |
| */ |
| |
| /** |
| * Allocate space for copying an object (this method <i>does not</i> |
| * copy the object, it only allocates space) |
| * |
| * @param original A reference to the original object |
| * @param bytes The size of the space to be allocated (in bytes) |
| * @param align The requested alignment. |
| * @param offset The alignment offset. |
| * @return The address of the first byte of the allocated region |
| */ |
| @Inline |
| public Address allocCopy(ObjectReference original, int bytes, |
| int align, int offset, int allocator) { |
| if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(allocator == MC.ALLOC_IMMORTAL); |
| |
| return immortal.alloc(bytes, align, offset); |
| } |
| |
| /** |
| * Perform any post-copy actions. |
| * |
| * @param object The newly allocated object |
| * @param typeRef the type reference for the instance being created |
| * @param bytes The size of the space to be allocated (in bytes) |
| */ |
| @Inline |
| public void postCopy(ObjectReference object, ObjectReference typeRef, |
| int bytes, int allocator) { |
| MC.immortalSpace.initializeHeader(object); |
| } |
| |
| /**************************************************************************** |
| * |
| * Collection |
| */ |
| |
| /** |
| * Perform a per-collector collection phase. |
| * |
| * @param phaseId The collection phase to perform |
| * @param primary Perform any single-threaded activities using this thread. |
| */ |
| @Inline |
| public final void collectionPhase(short phaseId, boolean primary) { |
| if (phaseId == MC.PREPARE) { |
| currentTrace = TRACE_MARK; |
| super.collectionPhase(phaseId, primary); |
| markTrace.prepare(); |
| return; |
| } |
| |
| if (phaseId == MC.CLOSURE) { |
| markTrace.completeTrace(); |
| return; |
| } |
| |
| if (phaseId == MC.RELEASE) { |
| markTrace.release(); |
| super.collectionPhase(phaseId, primary); |
| return; |
| } |
| |
| if (phaseId == MC.PREPARE_FORWARD) { |
| currentTrace = TRACE_FORWARD; |
| super.collectionPhase(MC.PREPARE, primary); |
| forwardTrace.prepare(); |
| return; |
| } |
| |
| if (phaseId == MC.FORWARD_CLOSURE) { |
| forwardTrace.completeTrace(); |
| return; |
| } |
| |
| if (phaseId == MC.RELEASE_FORWARD) { |
| forwardTrace.release(); |
| super.collectionPhase(MC.RELEASE, primary); |
| return; |
| } |
| |
| super.collectionPhase(phaseId, primary); |
| } |
| |
| /**************************************************************************** |
| * |
| * Miscellaneous |
| */ |
| |
| /** @return The current trace instance. */ |
| public final TraceLocal getCurrentTrace() { |
| if (currentTrace == TRACE_MARK) { |
| return markTrace; |
| } else { |
| return forwardTrace; |
| } |
| } |
| |
| /** @return The active global plan as an <code>MC</code> instance. */ |
| @Inline |
| private static MC global() { |
| return (MC) VM.activePlan.global(); |
| } |
| } |